1. Field of the Invention
The present invention relates to air valve caps for inflation apparatus and more particularly, to a Schrader (American) valve/Presta (French) valve dual-purpose valve cap.
2. Description of the Related Art
The most commonly seen air valves are the Schrader valve and the Presta valve. The Schrader valve is also called American valve having an outer diameter 8 mm and used on virtually every motor vehicle in the world today. The Presta valve is also called Sclaverand valve or French valve having an outer diameter 6 mm and commonly found in high pressure road style and many mountain bicycle inner tubes. These two types of air valves are different in diameter and structure and use a different valve cap. To solve this problem, dual-purpose valve caps were created. Conventional dual-purpose valve caps commonly have an American valve and a French valve arranged in parallel at one end and a lever located on the other end. When the air valve of the inflatable object to be inflated is connected to the American valve or French valve, operate the lever to squeeze a rubber socket in the dual-purpose valve cap, thereby elastically deforming the rubber socket and forcing the elastically deformed rubber socket to seize the air valve of the inflatable object. These dual-purpose valve caps further include a manual or automatic air passage switching mechanism to match the air valve inflation operation. These conventional dual-purpose valve caps commonly have a complicated structure and large size, and require a large operation space. Further, the air valve of the inflatable object may be disconnected from the rubber socket accidentally during the inflation operation.